Transcript Wed 2.6 Ratios, Rates, Conversions

1. Solve 14 – 7(b + 2) = 16
2. Bricklayers use the formula n = 7Lh to
estimate the number (n) of bricks needed to
build a wall.
a. Solve the formula for h.
b. Estimate the height of the wall 28 ft long and
requires 1568 bricks.
Clear Targets: TSWBAT
 Convert rates and unit measures
 Use ratios to compare 2 numbers
Literal Equations
Consider a class that has 25 students and 11
are boys.
a. The ratio of boys to total students is 11:25
b. What is the ratio of girls to boys?
Watch the order in which the ratios are
asked for
Rates and Ratios
Ratio that compares quantities in
different measures.
A rate with a denominator of 1.
Which store offers the best deal?
Store A: $25 for 2 shirts; Store B: $45 for 4 shirt;
Store C: $30 for 3 shirts.
Write each price as a ratio, then as a unit rate to
compare.
Unit Rates and Proportions
A brand of apple juice costs $1.56
for 48 ounces. What is the unit rate?
Proportion: equality between ratios
Can cross multiply to find the unit rate.
48x = 1.56
Conversion Rates
Conversion factor is a ratio of 2 equal
measures in different units.
Convert 63 yds. to feet
1. Choose appropriate conversion
factor.
2. Set up problem.
Conversion Rates
The fastest recorded speed for an eastern
gray kangaroo is 40 mi per hour. What is the
kangaroo’s speed in feet per second?
Set up problem with conversion factors.
40 mi • 5280 ft • 1 h • 1 min
60 min
60 s
1h
1 mi
Cross out like units and multiply.
The kangaroo’s speed is about 58.7 ft/s.
Conversion Rates
A student ran the 50 yd dash in 5.8 s.
At what speed did the student run in mph?
Conversion Rates
Homework / Classwork
Page 121
Problems
(1-4, 9, 10,11,14,17,20,23,24,26,28,30)